Method and apparatus for magnetically controlling endoscopes in body lumens and cavities

ABSTRACT

A magnetically navigable endoscope system includes an endoscope having a proximal end and a distal end, the distal end having a magnetic body; a component which transmits an image, associated with the distal end; a display component for displaying the image; a magnetic field generating apparatus for generating a magnetic field to orient the magnetic body and thus the distal end of the endoscope; and a controller coordinated with the display for controlling the magnetic field generating apparatus to selectively change the magnetic field to change the orientation of the magnetic body and thus the distal end of the endoscope.

FIELD OF THE INVENTION

This invention relates to magnetically controlling endoscopes, and inparticular to a method and apparatus for magnetically controllingendoscopes in body lumens and cavities.

BACKGROUND OF THE INVENTION

Endoscopes, which allow viewing of the interior of body lumens andcavities, are increasingly used in conducting medical procedures. One ofthe greatest difficulties in using endoscopes is navigating the distalend of the endoscope within the body to the procedure site. Standardendoscopes are steered using articulation wires secured to the distalend and which extend to the proximal end, where they can be operated bymechanisms incorporated in the proximal end of the endoscope. Thearticulation wires pull the distal end of the endoscope, causing it toarticulate in the desired direction. Some endoscopes have a single planeof articulation, and navigation is affected by a combination ofarticulation and rotation of the endoscope. Other endoscopes have twoplanes of articulation, and navigation is effected by combinations ofmovement in the two planes. Neither of these types of endoscopesprovides simple and easy omnidirectional navigation. Another problemwith wire-controlled endoscopes is that the control over the movement ofthe tip of the endoscope diminishes with each successive bend in theendoscope, so as the endoscope is navigated through a particularlytortuous path through the body, navigation becomes increasinglydifficult.

Magnetic navigation of an endoscope eliminates the difficultiesencountered with mechanical navigation. A magnetic field can begenerated to orient the tip of the endoscope in virtually any direction,and is not limited to movement in one or two planes. Furthermore, tipdeflection is based solely on the strength of the magnetic field, andthus navigation is not affected by the path of the endoscope. However,it can be difficult for a medical professional to quickly and easilycontrol the magnetic field in order to effectively magnetically navigatean endoscope. What has been needed is an effective way of controllingthe application of magnetic fields to both orient and move magneticdevices, such as endoscopes.

SUMMARY OF THE INVENTION

The present invention provides a method and apparatus for magneticallynavigating devices such as an endoscope through body lumens andcavities. Generally the magnetically navigable endoscope system of thepresent invention comprises an endoscope with a magnetic member, acomponent in the endoscope which transmits an image associated with theendoscope's distal end, a display to view the image, an input device, acomputer with image processing software and a magnetic field generatingapparatus for generating a magnetic field to orient the magnetic member.The endoscope construction can be similar to a standard endoscopewithout the articulation wires. The magnetic member is contained in thedistal segment of the endoscope to orient the endoscope upon theapplication of an external magnetic field. The video image (e.g., aoptical, ultrasound, or infrared image) from the endoscope is sent to acomputer with image processing software, which provides general graphicsoverlays (i.e. lines and text) and image rotation functions. An inputdevice such as a controller connected to the computer allows a physicianto specify the change in deflection angle of the endoscope's distal end.As the controller is moved to the left, right, forward or backwardpositions, the computer senses the controller's position and accordinglyprocesses a change in the magnetic field direction. The computer thencauses the magnetic field generating apparatus to apply the new magneticfield direction.

Generally the method of magnetically navigating endoscopes of thepresent invention comprises specifying the direction to orient theendoscope using a variety of input devices and user interfaces, whilethe endoscope is manually or automatically advanced in the body lumen orcavity.

The method of the present invention can also be used in navigating thedistal end of an endoscope in the bronchia; navigating the distal end ofan endoscope in the brain; navigating the distal end of an endoscope inthe colon and/or intestines; and navigating the distal end of theendoscope in the heart.

The endoscopes used with the method of this invention are preferablyconstructed to facilitate the recovery and re-integration of the imagebundle, the light bundle, and the magnetics into new endoscopes, so thatthe endoscopes can be made disposable. Thus the entire endoscope of thepresent invention can be made re-usable or disposable.

The magnetically navigable endoscope system of the present inventionallows a health care professional to quickly and intuitively navigatethe endoscopes through body lumens and cavities. In the preferredembodiment, the system interface allows the health care professional tomove the endoscope through the body without having to get involved indirectly controlling the magnetic field direction and strength. This isachieved by allowing the physician to directly visualize the body lumenor cavity in which the endoscope is located, and navigate based on thisviewed image.

According to the method and apparatus of this invention, the distal endof an endoscope can be oriented in virtually any direction. Moreover,the navigation is unaffected by the path of the endoscope. These andother features and advantages will be in part apparent, and in partpointed out hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of an apparatus for magnetically controllingendoscopes according to the principles of this invention;

FIG. 2 is a schematic side elevation view of an endoscope for use withthis invention;

FIG. 3 is a transverse cross-sectional view of the endoscope;

FIG. 4 is a side elevation view of the distal end portion of theendoscope;

FIG. 5 is a perspective view of a first alternate construction of thedistal end portion of the endoscope;

FIG. 6 is a side elevation view of a second alternate construction ofthe distal end of the endoscope;

FIG. 7 is a longitudinal cross-sectional view of a third alternateconstruction of the distal end of the endoscope;

FIG. 8 is a side elevation view of an alternate endoscope construction,including an integral controller;

FIG. 9 is a front elevation view of a possible display for use innavigating endoscopes according to the present invention; and

FIG. 10 is an end elevation view of the distal end of an endoscopeprovided with a plurality of pressure sensors around the circumferenceof its distal end;

FIG. 11 is a perspective view of the distal end of the endoscope showingan exemplary construction of the pressure sensors

FIG. 12 is a view of the distal end of an endoscope being navigatingwithin a kidney.

Corresponding reference numerals indicate corresponding parts throughoutthe several views of the drawings.

DETAILED DESCRIPTION OF THE INVENTION

A system for navigating endoscopes through body lumens and cavities isindicated generally as 20 in FIG. 1. The system 20 comprises anendoscope 22, a light. source 24 connected to the endoscope to providelight to illuminate the body lumen or cavity surrounding the distal endof the endoscope, an imaging device 26, for example a camera, forcapturing images of the body lumen or cavity surrounding the distal endof the endoscope and a computer 28 for processing the image captured bythe imaging device 26 and displaying the image on a display 30. Ofcourse instead of a camera for capturing optical images, the imagingdevice could be an ultrasonic imaging device or an infrared imagingdevice, or some other suitable imaging device. The computer 28 is alsoconnected to a controller, such as a controller 32, for receiving inputfor controlling endoscope 22, and processing the input to create anoutput control signal to the magnetic field generating device 34 tocontrol the magnetic field applied to the distal end of the endoscope tomove (orient and/or advance) the distal end of the endoscope in thedesired direction.

The magnetic field generating device 34 is one that is capable ofgenerating a magnetic field of selected direction and strength in anoperating volume within a patient. An example of such a system is thatdisclosed in co-assigned, copending U.S. patent application Ser. No.09/211,723, field Dec. 14, 1998, entitled Open Field System for MagneticSurgery, incorporated herein by reference. The magnetic field directionand field strength in this system can be controlled by controlling thecurrents applied to the electromagnetic coils comprising the system. Oneof ordinary skill in the art could easily implement a software algorithmto control a system which provides appropriate magnetic field directionand strength to achieve a selected orientation or movement. The magneticfield for navigating the endoscope in accordance with the presentinvention could also be provided with an articulated magnet, for examplelike that disclosed in co-assigned, co-pending U.S. Patent ApplicationSer. No. 60/118,959, filed Feb. 4, 1999, entitled An Efficient PermanentMagnet Means to Produce an Arbitrary Field and incorporated herein byreference.

The endoscope 22 is best shown in FIG. 2. The endoscope 22 has aproximal end 36 and a distal end 38. As shown in FIG. 3, the endoscopehas a plurality of inner lumens, depending upon the application. In thispreferred embodiment there are four such lumens 42, 44, 46 and 48.

The lumen 42 forms a working channel 52 extending the entire length ofthe endoscope 22, and providing a passage for one or more surgicalinstruments.

The lumen 44 forms a passage for light bundle 54 which is preferably abundle of optical fibers extending substantially the length of theendoscope 22. The proximal end of the light bundle 54 is opticallyconnected to a connector 56 on the side of the proximal end portion ofthe endoscope 22, and the distal end of the light bundle 54 terminatesat the distal end 38 of the endoscope. The light source 24 is connectedvia connector 56 to the light bundle 54 to illuminate the areasurrounding the distal end 38 of the endoscope 22. Of course, with animaging system other than an optical system, e.g., ultrasonic orinfrared imaging, the light source 24 is not necessary.

The lumen 46 forms a passage for image path 56 which, in the case of anoptical imaging device 26, is preferably a bundle of optical fibersextending substantially the length of the endoscope 22. In the case ofan ultrasonic or infrared imaging device 26, the imaging path 56 couldbe a wire or cable. The proximal end of the image path 56 is connectedto a connector 60 on the distal end of the endoscope 22, and the distalend of the image bundle 56 terminates at the distal end 38 of theendoscope. The imaging device 26 is connected via connector 60 to theimage path 56 to receive images from the area surrounding the distal end38 of the endoscope 22. The imaging device 26 is in turn connected tothe computer 28, which processes the image signal from the imagingdevice and displays in the image on the display 30.

The lumen 48 forms an optional magnet channel 60 which allows one ormore magnets 62 to be positioned along the length of the endoscope 22 topermit the endoscope to be moved (oriented and/or advanced) by anapplied magnetic field. The magnets could be made either of a permanentmagnetic material, such as neodymium-iron-boron, or of a permeablemagnetic material, such as cold rolled steel or Hiperco™. The magnets 62are shaped to maximize their field strength for their size, and thus aretypically cylindrical, and are preferably placed adjacent the distal end38 of the endoscope 22. The distal end portion of the endoscope, showingthe position of the magnet 62, is shown in FIG. 4.

The endoscope 22, and in particular the lumens 42, 44, 46, and 48, andthe space surrounding the lumens 42, 44, 46, and 48, can be filled witha filler to secure the components in the endoscope. However portions ofthe filler along the length of the endoscope can be selectively removedby leaching to reduce the weight and stiffness of the catheter. For someapplications, substantially all of the filler between the proximal anddistal ends will be leached away, leaving the filler at the proximal anddistal ends to hold the components in their proper orientation. It isalso possible that selected portions of the filler material between theproximal and distal ends of the endoscope are leached.

The flexibility of the endoscope can vary along its length, to suit theparticular function of the endoscope. In most embodiments, it ispreferred that at least the distal end portion be highly flexible sothat it can readily align with an applied magnetic field. For mostapplications, a highly flexible portion at least 3 cm long should besufficient. The flexibility is preferably such that the distal end ofthe endoscope can bend at least about 120° with respect to thelongitudinal axis of the immediately proximal portion of the endoscope,with a radius of curvature of about 2 cm or less.

A first alternate construction of the distal end of the endoscope isshown in FIG. 5. As shown in FIG. 5 the portion of the endoscopeadjacent the distal end 38 can include a helical coil 64. The coil 64can be made of a highly flexible permeable magnetic material to providean alignment force of the end portion of the endoscope under an appliedmagnetic field. The coil 64 could also be made of a non-magneticmaterial to simply provide axial stiffness when the tip is arched by themagnetic field.

A second alternate construction of the distal end 38 of the endoscope 22is shown in FIG. 6, in which the distal end of the endoscope is providedwith a machined tip 66, preferably made from a permanent or permeablemagnetic material. The machined tip 66 can provide the sole oradditional alignment force for the tip to orient with the externallyapplied magnetic field.

A third alternate construction of the distal end 38 of the endoscope 22is shown in FIG. 7, in which multiple magnet bodies are used to achievegreater magnetic torque. As shown in FIG. 7, the distal end section ofthe third alternate construction of the endoscope contains a pluralityof magnet rings 67. The rings 67 are retained in the distal end section,and do not significantly impair the flexibility of the distal endsection. The rings 67 provide sufficient magnet material so that asubstantial torque can be applied to the distal end of the endoscope.

An alternate endoscope for use with this invention is indicatedgenerally as 22′ in FIG. 8. Endoscope 22′ is similar in construction toendoscope 22, and corresponding parts are identified with correspondingreference numerals. Unlike endoscope 22, endoscope 22′ includes anintegral controller 68 which can be used instead of the controller 32.This allows the physician to navigate the endoscope 22′ without removinghis or her hands from the endoscope. The controller 68 could consist ofa joystick attached to the endoscope's proximal end which the physiciancan manipulate to control the distal end of the endoscope. Thecontroller 68 could alternatively consist of one or one or more sensorsfor sensing the orientation of the proximal end of the endoscope, and inwhich this sensed orientation can indicate the desired direction for thedistal end of the endoscope. Thus by simply manipulating the proximalend of the endoscope, the physician can control the distal end of theendoscope.

The computer 28 processes the image from the imaging device 26, adds anoverlay, such as that shown in FIG. 9, and displays the image in anorientation intuitively coordinated with the controller 32. In thispreferred embodiment, the controller and computer operate to control theexternally applied magnetic field so that moving the controller leftcauses the magnetic field generating device 24 to change the appliedmagnetic field and move the distal end 38 of the endoscope 22 left asviewed on the display 30. Moving the controller 32 right causes themagnetic field generating device 24 to change the applied magnetic fieldand move the distal end 38 of the endoscope 22 right as viewed on thedisplay 30. Moving the controller 32 forward causes the magnetic fieldgenerating device 24 to change the applied magnetic field and move thedistal end 38 of the endoscope down as viewed on the display 30. Movingthe controller 32 backward causes the magnetic field generating device24 to change the applied magnetic field and move the distal end 38 ofthe endoscope 22 up as viewed on the display 30. However, thesecorresponding directions could be swapped, depending upon the user'spreference.

To facilitate navigation it is desirable to have the display imagecoordinated with the controls for navigating the medical device. Thiscan be accomplished in several different ways. The display image and thecontrol can be periodically synchronized. The user can move the controlin a preselected direction, for example, up, observe which direction theimage on the display screen moves, and mark this direction on thedisplay as the “up” direction. This marking can be conveniently done bymoving a cursor or other indicator on the display with a mouse orsimilar input device. The user positions the cursor or other indicatorto indicate the preselected direction and triggers the calibration, forexample by clicking the mouse. The computer can then reprocess andreorient the image so that it is intuitively oriented with respect tothe control. Alternatively one or more indicia 70, indicating theorientation of the image can be displayed on the display. The physiciancan use the indicia to properly operate the controller. For example, ifthe physician wants to move the endoscope in the direction of the “U”indicia 70, the physician moves the controller back—regardless of wherethe “U” indicia is actually located on the display 30. Similarly, if thephysician wants to move the controller in the direction of the “R”indicia 70, the physician moves the controller to the right—regardlessof where the “R” indicia is actually located on the display 30.

Another way of coordinating the display image with the controls fornavigating the medical device is to provide some orientation indicatoron the medical device so that the actual orientation can be determined.For example a radiopaque marker can be included on the medical device sothat the orientation of the medical device can be determined visually onthe display or automatically through image processing. Alternatively,some other system for remotely determining the orientation of themedical device, such as an optic sensor, a magnetic sensor, or anultrasonic sensor can be used to obtain information about theorientation of the medical device. The computer can process theinformation about the orientation of the medical device and eitherre-orient the displayed image, or adjust the operation of the magneticfield control to intuitively coordinate the image and the operation ofthe control.

Of course, the image displayed on the display 30 can be orientedabsolutely, i.e. so that vertical in the displayed image corresponds toactual vertical, and the controller coordinated so that the movement ofthe controller back moves the endoscope up, forward moves the endoscopedown, and left moves the endoscope left, and right moves the endoscoperight. Alternatively the image displayed on the display can be orientedrelative to the control, such that regardless of the actual orientation,moving the control back moves the endoscope up as viewed on the display,moving the control forward moves the endoscope down as viewed on thedisplay, moving the control left moves the endoscope left as viewed onthe display, and moving the control right moves the endoscope right asviewed in the display.

The magnetically navigable endoscope system of the present invention canalso include one or more sensors 80, triggered by contact with ananatomical structure such as the wall of a body lumen or cavity. Asshown in FIGS. 10 and 11, these sensors 80 can be distributed around thedistal end of the endoscope to sense contact anywhere around thecircumference of the distal end of the endoscope. The sensors may be,for example a spring contact 82 projecting from the exterior sidewall ofthe endoscope, resiliently biased away from contact 84, such thatpressure (such as from the endoscope contacting an internal bodystructure such as the wall of a lumen or cavity) forces the contactstogether. A controller, such as a computer, monitors the signals fromthe sensors and can control the magnetic field generating apparatus toselectively modify the magnetic field to change the orientation of themagnetic body such that the distal end of the endoscope remains in thedesired position within the body lumen or cavity in which it is located.For example in some applications, it will be desirable that theendoscope remain substantially centered within a body lumen or cavity,to facilitate its advancement in the lumen or cavity. In otherapplications, it will be desirable that the endoscope remain in contactwith one of the walls of the body lumen or cavity, for example forelectrical mapping of the tissue or some other procedure. The system caninclude an advancing mechanism for advancing the endoscope, and aninterlock for preventing operation of the advancing mechanism when apre-determined number of sensors are triggered.

In a preferred mode of operation, the distal end of the endoscope islocalized, for example by manually identifying the distal end of theendoscope on the displays of a bi-planar fluoroscopic imaging system.The physician can easily do this with a computer mouse or other inputdevice, by manipulating a cursor over the end and clicking. Identifyingthe position of the distal end of the endoscope on two different planarimages, uniquely identifies the end of the endoscope inthree-dimensional space. The location of the distal end of the endoscopeis then registered to a pre-operative image set such as an MR or CTimage set. Once the distal end of the endoscope is registered on thepre-operative image set, the physician then identifies a direction onthe preoperative image set. The magnetic field generating apparatus thengenerates the appropriate magnetic field to move (orient and/or advance)the distal end of the endoscope in the identified direction.

Alternatively, after the endoscope is localized, and the positionregistered on a pre-operative MR or CT image set, the physician couldidentify inputs a volume over which to move (orient and/or advance) theendoscope. This can be conveniently done by indicating the volume on apreoperative MR or CT image set. The magnetic field generating apparatusthen generates the appropriate magnetic field to move (orient and/oradvance) the distal end of the endoscope in the specified volume.

The method of the present invention can be used for navigating medicaldevices virtually anywhere in the body. For example the method of thepresent invention can be used with ureterscopes, navigating the distalend of the endoscope in the calix of the kidney, as shown in FIG. 12.

1. A magnetically navigable endoscope system comprising: an endoscopehaving a proximal end and a distal end, the distal end having a magneticbody; an imaging device which transmits an image, associated with thedistal end; a display component for displaying the image; a magneticfield generating apparatus for generating a magnetic field to move themagnetic body and thus the distal end of the endoscope; a controllercoordinated with the display for controlling the magnetic fieldgenerating apparatus to apply a magnetic field to change the position ofthe magnetic body and thus the position of the distal end of theendoscope.
 2. The magnetically navigable endoscope system according toclaim 1 wherein the controller controls the magnetic field generatingapparatus to apply a magnetic field of a specific direction to changethe orientation of the magnetic body and thus the orientation of thedistal end of the endoscope.
 3. The magnetically navigable endoscopesystem according to claim 1 wherein the controller controls the magneticfield generating apparatus to apply a magnetic gradient to move themagnetic body and thus the location of the distal end of the endoscope.4. The magnetically navigable endoscope system according to claim 1wherein the controller controls the magnetic field generating apparatusto apply a magnetic field and a magnetic gradient to apply a magneticfield of a specific direction to change the orientation of the magneticbody and to apply a magnetic gradient to move the magnetic body and thusthe orientation and location of the distal end of the endoscope.
 5. Themagnetically navigable endoscope system according to claim 1 wherein thecontroller is on the endoscope, adjacent the proximal end.
 6. Themagnetically navigable endoscope system according to claim 1 wherein thecontroller is operable in at least two mutually perpendiculardirections, movement in which causes the magnetic field generatingapparatus to change the magnetic field to move the distal end of theendoscope in two mutually perpendicular directions.
 7. The magneticallynavigable endoscope system according to claim 1 wherein the displayincludes indicia indicating an orientation of the displayed image, andwherein the controller is operable in at least two mutuallyperpendicular directions, and movement in the first direction causes themagnetic field generating apparatus to change the magnetic field to movethe distal end of the endoscope in a first plane relative to theindicia, and movement in the second direction causes the magnetic fieldgenerating apparatus to change the magnetic field to move the distal endof the endoscope in a second plane, perpendicular to the first place. 8.The magnetically navigable endoscope system according to claim 7 whereinthe first plane is aligned with the indicia.
 9. The magneticallynavigable endoscope system according to claim 6, wherein the display hasvertical and horizontal directions, and wherein the movement of thecontroller in one of the mutually perpendicular directions causes themagnetic field generating apparatus to change the magnetic field to movethe distal end of the endoscope in the vertical direction as displayedon the display, and wherein the movement of the controller in the otherof the mutually perpendicular direction causes the magnetic fieldgenerating apparatus to change the magnetic field to move the distal endof the endoscope in the horizontal direction as displayed on thedisplay.
 10. The magnetically navigable endoscope system according toclaim 9 further comprising a signal processor orienting the image on thedisplay so that the vertically “up” direction of the image is orientedat the top of the display regardless of the actual orientation of theaxis of the endoscope.
 11. The magnet assembly according to claim 1wherein the endoscope includes a magnet channel, and wherein there is atleast one magnet body disposed in the magnet channel adjacent the distalend.
 12. The magnet assembly according to claim 1 wherein there are aplurality of magnet bodies in the distal end portion of the endoscope.13. The magnet assembly according to claim 1 wherein the magnet bodycomprises a permanent magnetic material.
 14. The magnet assemblyaccording to claim 1 wherein the magnet body comprises a permeablemagnetic material.
 15. A magnetically navigable endoscope systemcomprising: an endoscope having a proximal end and a distal end, thedistal end having a magnetic body; a component which transmits an image,associated with the distal end; a two-dimensional display for displayingthe image from the image-transmitting component, the display having avertical and horizontal direction; a magnetic field generating apparatusfor generating a magnetic field to orient the magnetic body and thus thedistal end of the endoscope; a controller for controlling the magneticfield generating apparatus to selectively apply to apply a magneticfield to change the position of the magnetic body and thus the positionof the distal end of the endoscope, the controller operable in at leasttwo mutually perpendicular directions, movement of the controller in oneof the mutually perpendicular directions causing the magnetic fieldgenerating apparatus to change the magnetic field to move the distal endof the endoscope in the vertical direction as displayed on the display,and wherein the movement of the controller in the other of the mutuallyperpendicular direction causes the magnetic field generating apparatusto change the magnetic field to move the distal end of the endoscope inthe horizontal direction as displayed on the display.
 16. A method ofmagnetically navigating an endoscope, the method comprising displayingan image from the distal end of the endoscope on a display, the displayincluding an orientation indicia; and operating a controller to controlthe application of a magnetic field to the distal end of the endoscope,the controller being operable in at least two mutually perpendiculardirections, movement of the controller in one of the mutuallyperpendicular directions causing the magnetic field generating apparatusto apply a magnetic field to move the distal end of the endoscope in afirst plane relative to the orientation indicia on the display, andwherein the movement of the controller in the other of the mutuallyperpendicular directions causes the magnetic field generating apparatusto change the magnetic field to move the distal end of the endoscope ina second plane, perpendicular to the first plane.
 17. A method ofmagnetically navigating an endoscope, the method comprising displayingan image from the distal end of the endoscope on a display operating acontroller to control the application of a magnetic field to the distalend of the endoscope, the controller being operable in at least twomutually perpendicular directions, movement of the controller in one ofthe mutually perpendicular directions causing the magnetic fieldgenerating apparatus to change the magnetic field to move the distal endof the endoscope in the vertical direction as displayed on the display,and wherein the movement of the controller in the other of the mutualperpendicular directions causes the magnetic field generating apparatusto change the magnetic field to move the distal end of the endoscope inthe horizontal direction as displayed on the display.
 18. A magneticallynavigable endoscope system comprising: an endoscope having a proximalend and a distal end, the distal end having a magnetic body; a componentwhich transmits an image, associated with the distal end; atwo-dimensional display for displaying the image from theimage-transmitting component, the display having a vertical andhorizontal direction; a magnetic field generating apparatus forgenerating a magnetic field to move the magnetic body and thus thedistal end of the endoscope; and a controller for identifying the volumeover which to orient the endoscope and controlling the magnetic fieldgenerating apparatus to selectively change the magnetic field to changethe orientation of the magnetic body and thus the distal end of theendoscope over the specified volume.
 19. A method of magneticallycontrolling an endoscope in body lumens and cavities, the methodcomprising: localizing the distal end of an endoscope; registering thelocation of the distal end of the endoscope to a pre-operative image setsuch as an MR or CT; identifying a direction on the pre-operative imageset; and controlling the magnetic field generating apparatus to move thedistal end of the endoscope in the identified direction.
 20. The methodof magnetically controlling an endoscope according to claim 19 whereinthe magnetic field generating apparatus generates a magnetic field inthe identified direction to orient the distal end of the endoscope inthe identified direction.
 21. The method of magnetically controlling anendoscope according to claim 19 wherein the magnetic field generatingapparatus generates a magnetic field with a gradient in the identifieddirection to advance the distal end of the endoscope in the identifieddirection.
 22. The method of magnetically controlling an endoscopeaccording to claim 19 wherein the magnetic field generating apparatusgenerates a magnetic field with a field direction and gradient in theidentified direction to orient and advance the distal end of theendoscope in the identified direction.
 23. A method of magneticallycontrolling an endoscope in body lumens and cavities, the methodcomprising: localizing the distal end of an endoscope; registering thelocation of the distal end of the endoscope to a pre-operative image setsuch as MR or CT; programming a volume over which to movethe endoscope;and controlling the magnetic field generating apparatus to move thedistal end of the endoscope in the specified volume.
 24. A method ofmagnetically navigating an endoscope in a body lumen or cavity with anapplied magnetic field, the method comprising: displaying an image fromthe distal end of the endoscope in an orientation relative to adirectional control such that operation of the directional control in aselected direction relative to the displayed image causes the appliedmagnetic field to change to move the distal end of the endoscope in acorresponding direction on the display, and operating the directionalcontrol corresponding to the desired direction as displayed upon thedisplayed image to apply a magnetic field to move the distal end in thedesired direction as displayed upon the displayed image.
 25. The methodaccording to claim 24 wherein operating the directional control appliesa magnetic field in the selected direction to orient the distal end ofthe endoscope in the desired direction.
 26. The method according toclaim 24 wherein operating the directional control applies a magneticfield with a gradient in the selected direction to advance the distalend of the endoscope in the desired direction.
 27. The method accordingto claim 24 wherein operating the directional control applies a magneticfield in a selected direction, and with a gradient in the selecteddirection to orient and advance the distal end of the endoscope in thedesired direction.
 28. The method according to claim 24 wherein the stepof displaying an image includes periodically reorienting the image byoperating the directional control to change the applied magnetic fieldto move the distal end of the endoscope. identifying the direction ofmovement of the distal end of the endoscope on the display; andreorienting the image on the display so that the direction of movementcaused by operating the control intuitively corresponds to thedirections on the displayed image.
 29. The method according to claim 24wherein the endoscope is navigated through one of the lungs, the urinarytract, or the gastrointestinal tract, brain, and heart.
 30. Amagnetically navigable endoscope system comprising: an endoscope havinga proximal end and a distal end, the distal end having a magnetic body;an imaging device which transmits an image, associated with the distalend; a plurality of sensors triggered by contact with the wall of a bodylumen or cavity, distributed around the distal end; a two-dimensionaldisplay for displaying the image from the imaging device, the displayhaving a vertical and horizontal direction; a magnetic field generatingapparatus for generating a magnetic field to orient the magnetic bodyand thus the distal end of the endoscope; a computer which monitorsfeedback of the wall contact sensors and adjusts the magnetic fieldgenerating apparatus to selectively modify the magnetic field to changethe orientation of the magnetic body such that the endoscope isautomatically positioned within the body lumen or cavity.
 31. The systemaccording to claim 30 wherein the computer that monitors the feedback ofthe wall contact sensors adjusts the magnetic field generating apparatusto selectively modify the magnetic field to position the endoscope ingenerally the center of the body lumen or cavity.
 32. The systemaccording to claim 30 wherein the computer that monitors the feedback ofthe wall contact sensors adjusts the magnetic field generating apparatusto selectively modify the magnetic field to position the endoscopegenerally adjacent a selected wall of the body lumen or cavity.
 33. Thesystem according to claim 30 further comprising an advancing mechanismfor advancing the endoscope.
 34. The system according to claim 33further comprising an interlock for preventing operation of theadvancing mechanism when a predetermined number of wall-sensors aretriggered.
 35. A magnetically controllable endoscope having a proximalend, a distal end, a magnetic body associated with the distal end, theendoscope having at least two sections along its length of differentflexibilities of its length.
 36. The magnetically controllable endoscopeaccording to claim 35, wherein the endoscope comprises a proximalsection and a distal section, and wherein the distal most section ismore flexible than the proximal section.
 37. The magneticallycontrollable endoscope according to claim 35 wherein the magnetic bodycomprises a permanent magnetic material.
 38. The magneticallycontrollable endoscope according to claim 35 wherein the magnetic bodycomprises a permeaable magnetic material.
 39. The magneticallycontrollable endoscope according to claim 35 further comprising a binderin the endoscope, and wherein the regions of different flexibility areformed by selective leaching of the binder.